Generally, dental clinics are provided with X-ray photographing apparatuses capable of performing X-ray photographing in order to treat teeth and various periodontal diseases or figure out a state of teeth and an alveolar bone for the purpose of correction of irregularities of the teeth, or the like.
The X-ray photographing apparatus used in the dental clinic transmits a predetermined amount of X-ray through a tooth portion, which is a body portion to be photographed, senses an intensity of the transmitted X-ray, converting the intensity of the transmitted X-ray into an electrical signal corresponding to the intensity of the transmitted X-ray, and transmits the electrical signal to a computer. In this case, the computer calculates intensities of X-rays of the respective points of photographed body portions and processes the intensity to obtain an image.
As the X-ray photographing apparatus described above, an X-ray photographing apparatus for a computerized tomography (CT) capable of photographing a three-dimensional stereoscopic image, an X-ray photographing apparatus for a panorama capable of photographing a two-dimensional plane image, and the like, have been mainly used.
The X-ray photographing apparatus for a CT, which is an imaging apparatus displaying a tomographic image of a human body that may not be displayed by general photographing, is a tomography apparatus transmitting an X-ray through the human body while rotating at a predetermined angle over 360°, collecting the transmitted X-ray through a detector such as a sensor, or the like, and reconfiguring an absorption value for a cross section of the human body to display the reconfigured absorption value as an image.
In addition, the X-ray photographing apparatus for a panorama, which photographs the entirety on the basis of an X-ray generating apparatus in a circumferential direction, is an apparatus capable of performing panorama photographing to view an entire tooth state and a temporomandibular joint at a glance.
However, there is a disadvantage that the X-ray photographing apparatus for a CT may obtain only a CT image and the X-ray photographing apparatus for a panorama may obtain only a panorama image.
In order to solve the problem described above, apparatuses capable of performing both of CT photographing and panorama photographing using one X-ray photographing apparatus have been suggested.
For example, Korean Patent No. 10-1401927 discloses an “X-ray Photographing Apparatus Combining Panorama and CT for Dental Clinic”.
In the X-ray photographing apparatus combining panorama and CT for a dental clinic, a panorama sensor and a CT sensor rotate around a concentric axis by a rotation driving portion, such that a mode is switched, and at the time of switching the mode, a rotary arm in which an X-ray light source portion is disposed horizontally moves so as to face an X-ray sensor portion to vary a distance between the X-ray light source portion and the X-ray sensor portion with respect to a subject to be examined, thereby adjusting an image magnification depending on each mode and performing photographing.
However, the X-ray photographing apparatus combining panorama and CT for a dental clinic as described above can not but use only one set panorama image magnification at the time of performing panorama photographing using the panorama sensor, and can not but use only one set CT image magnification also at the time of performing CT photographing using the CT sensor.
That is, since the X-ray photographing apparatus combining panorama and CT for a dental clinic may not finely adjust a magnification power depending on a size of a head of the subject to be examined or a photographing environment and can not but perform photographing by applying only a fixedly set magnification power, quality of an image is significantly deteriorated depending on the size of the head of the subject to be examined.
In addition, the X-ray photographing apparatus combining panorama and CT for a dental clinic is configured in a horizontal moving structure through a ball screw such as a horizontal driving motor, a rotary arm horizontal driving ball screw, a connection shaft fixing member, and the like, and when the rotary arm having a weight of 60 kg or more is horizontally moved through the ball screw, a load of the motor is increased. Therefore, a motor having a high capacity should be used. As a result, an entire weight of the rotary arm is increased, such that a volume of the rotary arm is increased, and a rotation driving force of the connection shaft connected to the rotary arm is increased.